Wear Rate Values Research Articles

Particle size effect on abrasive wear behavior of all-metal positive displacement motor and abrasive particles control

Abstract Downhole drilling operations expose all-metal positive displacement motors (AMPDM) to abrasives of different sizes, causing serious abrasive wear behavior. Controlling the entry of large particles into the motor by installing a filter can effectively reduce wear conditions and improve its lifespan. This study investigated the particle size effect on abrasive wear to seek an appropriate filter size for AMPDM. The multi-function tribo-tester was modified according to the actual working conditions of the stator and rotor. The tribological properties of stator material (nitrited 38CrMoAl steel) against rotor material (YL10.2 cemented carbide) were conducted using SiO2 particles with 1 to 500 μm sizes in the range on a pin-on-disc tribo-tester under wet sliding-vibration conditions. The results showed more complicated friction coefficient evolution characteristics for small particles, existing two stable stages. Two critical-size values of average wear rate and wear mechanism transformation are determined. The wear products of tribochemical reaction were determined. The filter porosity of about 200 μm may be an optimal selection to decrease wear. This work has developed new insights into how AMPDM responds to changing abrasive sizes and provides a proposal for controlling the entry size of abrasive particles.

Polytetrafluoroethylene and Aluminum Powder as an Alternative to Copper in Car Brakes Composite Friction Materials

Brakes are one of the most important systems of every vehicle. They have an undoubted impact on safety. Their effects produce wear products, which in the case of conventional composition of friction materials also means the content of copper in compounds emitted into the atmosphere. Its harmful effect makes it necessary to look for an alternative that will replace its excellent lubricating and thermal properties. This article presents prototype materials in which attempts were made to replace copper with powdered aluminum and polytetrafluoroethylene. Four types of samples were prepared—one group with a conventional composition, and three groups with an alternative composition, in different proportions. Using the previously developed methodology, friction tests were performed. As a result, the values of friction coefficients and abrasive wear rate were determined. The results show that the proposed material is characterized by lower values of the coefficient of friction and a higher value of the abrasive wear rate coefficient.

Investigation of tribological performance of PAI and PAI/graphite/PTFE composites under different mediums and working conditions

Purpose This study aims to investigate the tribological performance of neat polyamide-imide (PAI) and PAI composite (PAI + 12% graphite + 3% polytetrafluoroethylene [PTFE]) under varying mediums and conditions, including dry sliding, distilled water and seawater lubrication, to determine their suitability for high-stress applications. Design/methodology/approach Tribological tests were conducted using a pin-on-disc setup with AISI 316 L stainless steel (SS) as counterface. Experiments were carried out under loads of 150 and 300 N and sliding speeds of 1.5 and 3.0 m/s. Values of temperatures, friction coefficients and wear rates were recorded to analyze the effect of fillers and lubrication mediums. Findings The PAI composite outperformed the neat PAI under all conditions, showing significant reductions in friction coefficients and wear rates. Seawater lubrication yielded the best results, achieving friction coefficients of 0.05 and 0.01 and specific wear rates of 18.10−16 m²/N and 1.10 −15 m²/N, for neat PAI and PAI composite, respectively. Graphite and PTFE fillers enhanced lubrication, reduced surface temperatures and mitigated abrasive and adhesive wear mechanisms. Superior cooling and lubrication effects of the seawater contributed to these improvements. Originality/value Previous studies mainly focused on dry sliding and distilled water lubrication for the PAI and its composites, with no research on the seawater conditions. This study compares the tribological behaviors of the neat PAI and PAI composite against AISI 316 L SS under dry sliding, distilled water and seawater lubrication. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2024-0302/

Tribological properties of silicon carbide ceramic surfaces modified by polishing, grinding and laser radiation

In this work, we experimentally studied the influence of the texture of silicone carbide (SiC) ceramics formed by traditional (grinding and polishing) and promising (laser radiation) treatment methods on tribological properties (the friction coefficient and wear rate). Raman spectroscopy was used to study the phase composition. The friction and wear tests were conducted using the ball-on disk technique under unlubricated conditions. The friction coefficient was found to be significantly affected by the texture (roughness), which must be described by at least four three-dimensional roughness parameters. The higher the surface roughness of both mechanically- and laser-treated SiC, the higher the values of wear rate and friction coefficient are. Mechanical treatment forms a texture with a negatively asymmetric and flatted distribution of asperities. The shape and density of asperities on this texture affect the friction coefficient. A texture with a negatively asymmetric and peak shaped distribution of asperities is formed by laser radiation of SiC. The skewness and the density of asperities on this texture affect the friction coefficient.

Prediction of Wear Rate by a New Direct Method Using the Friction Coefficient Curve

This work aims to introduce a new method to predict the wear rate accurately and quickly. Using techniques such as laser scanning confocal microscopy can take a long time to estimate the wear of the experimental alloys in situ. Developing a new method based on calculating the area under the early stages of the friction curve can be a useful and quick tool for estimating wear rate values and comparing wear between different alloys and conditions. The results validated the application of this new method with a regression coefficient of 0.98. This work also demonstrates that wear in the early stages accounts for the highest wear, indicating that the friction coefficient in the steady-state is not always a reliable indicator of the total wear rate. Hardness can be a more influencing parameter on wear rate than steady-state friction coefficient. Using the new method can help reduce time and predict wear more accurately of different alloys.

Application of the MULTIMOORA Method to Evaluate Performance Results of Red Mud Reinforced Bronze Matrix Brake Pads

The objective of this study is to investigate the effectiveness of the MULTIMOORA method strengthened with AHP to select the most suitable pad material among metal matrix composite brake pad materials reinforced with different proportions of red mud according to the criteria determining the efficiency of brake performance. For this purpose, five different brake pad samples reinforced with red mud, an industrial waste, at different weight ratios (0%, 2%, 4%, 6%, 8%) were produced and the physical, mechanical, and tribological properties of the pro-duced materials were characterized. Tribological characterization tests were carried out in accordance with TSE 555 using a specially designed brake dynamometer. The average coefficient of friction, specific wear rate, friction stability, hardness, density, and TRS values, which repre-sent important performance indicators of the pad material, were used as criteria for the selec-tion of pad material. According to the AHP method, the importance levels of these criteria in terms of brake performance were determined as 0.423, 0.205, 0.205, 0.088, 0.051, and 0.028, respectively. As a result of the evaluation made using the MULTIMOORA and MOOSRA method, it was determined that the RM-8 sample showed the best result in terms of brake performance among all samples. In addition, this material was followed by RM-6, RM-4, RM-0 and RM-2 samples, respectively. The findings of this study indicate that the MULTIMOORA method is an effective and reliable approach for selecting the optimal pad material among alterna-tives, according to the specified criteria.

Effect of titanium oxide nano‐filler on mechanical and sliding wear properties of hairy cotton grass fibre reinforced epoxy composites

AbstractThis study explores the synergistic influence of hybridizing titanium oxide (TiO2) filler on the mechanical properties and sliding wear behavior of epoxy composites reinforced with hairy cotton grass (HCG) fibres. The experimental results reveals that the combination with 9 wt‐% HCG/4 wt‐% titanium oxide observed better mechanical results (tensile‐51.03 MPa, flexural‐28.66 MPa, and impact energy‐3.1 J) whereas higher hardness (40.77 HV) achieved at 9 wt‐% hairy cotton grass/6 wt‐% titanium oxide composites. There is deterioration in mechanical results at higher titanium oxide (6 wt‐%) loading due to uneven distribution and particle agglomeration in hairy cotton grass‐epoxy composites. The design of expert was generated by using control parameters, sliding velocity (1 m ⋅ s−1–4 m ⋅ s−1), TiO2 content (0 wt‐%–6 wt‐%), and normal load (15 N–30 N) respectively. The optimization of the sliding wear rate was analysed by the Taguchi approach followed by an analysis of variance used for evaluating the significant of control parameters. The results showed a combination with significance sliding velocity of 1 ms−1 (78.15 %)>titanium oxide content of 6 wt‐% (20.28 %) >normal load of 30 N (1.57 %) exhibited an optimum value of specific wear rate.

A comparative study of thermal sprayed Al2O3-TiO2 coatings on PM AISI 316L

A comparative study of thermal sprayed Al2O3-TiO2 coatings on PM AISI 316L

Ball-on-Disk Wear Maps for Bearing Steel–Hard Anodized EN AW-6082 Aluminum Alloy Tribocouple in Dry Sliding Conditions

In recent years, Golden Hard Anodizing (G.H.A.®) has been developed as a variant of the traditional hard anodizing process with the addition of Ag+ ions in the nanoporous structure. The tribological properties of this innovative surface treatment are still not well understood. In this study, ball-on-disk tests were conducted in dry sliding conditions using 100Cr6 (AISI 52100) bearing steel balls as a counterbody and GHA®-anodized EN AW-6082 aluminum alloy disks. The novelty of this work lies in the mapping of the wear properties of the tribocouple under different test conditions for a better comparison of the results. Three different normal loads (equal to 5, 10, and 15 N) and three different reciprocating frequencies (equal to 2, 3, and 4 Hz) were selected to investigate a spectrum of operating conditions for polished and unpolished G.H.A.®-anodized EN AW-6082 aluminum alloy. Quantitative wear maps were built based on the resulting wear rate values to define the critical operating limits of the considered tribocouple. The results suggest that the coefficient of friction (COF) was independent of test conditions, while different wear maps were found for polished and non-polished surfaces. Polishing before anodizing permitted the acquisition of lower wear for the anodized disks and the steel balls.

Powder Metallurgical Processing of Al–5 wt% Cu Matrix Composites Reinforced with MoSi2 and WSi2 Particulates

Herein, investigations on the microstructural, physical, and mechanical properties of molybdenum disilicide (MoSi2)‐ and tungsten disilicide (WSi2)‐reinforced aluminum (Al)–copper (Cu) matrix composites are reported. Powder metallurgy methods such as mechanochemical synthesis (MCS), mechanical alloying (MA), cold pressing, and pressureless sintering are combined to produce composites. First of all, MoSi2 and WSi2 nanoparticles are synthesized by MCS and selective acid leaching, yielding reinforcement materials for Al–Cu matrix. Powder blends consisting of 95 wt% Al and 5 wt% Cu are mixed with metal disilicides at different weight percentages (1, 2, and 5 wt%). MA for 4 h is conducted on these overall blends using a high‐energy ball mill. Microstructural and thermal properties of the as‐blended and mechanically alloyed powders are determined, and then they are compacted under 450 MPa and sintered at 550 °C for 2 h. Mechanical characterization of the composites reveals an increase in hardness and wear resistance with an increasing amount of reinforcement content. Among bulk samples, 5 wt% WSi2‐reinforced composites have the highest microhardness (165 ± 15 HV) and lowest wear rate (1.69 × 106 μm3 Nm−1) values. However, under the compression forces, the highest toughness and strength are obtained from 2 wt%‐reinforced composites.

Impact of deposition pressure on the structural, nanomechanical, and tribological properties of δ-TaN coatings deposited via magnetron sputtering on Ti6Al7Nb alloy

In the present study, δ-TaN thin films were deposited by reactive magnetron sputtering (physical vapour deposition) on Ti6Al7Nb alloy by varying the deposition pressure (0.8–0.2 Pa). Their crystalline structure, chemical composition, surface roughness, and surface morphology were investigated by using grazing incidence X-ray diffraction, energy dispersive spectroscopy, scanning probe microscope, and field emission scanning electron microscopy (FESEM), respectively. Structural analysis results confirmed the deposition of cubic δ-TaN thin films along the (111) basal plane; moreover, spherical dome-like surface morphology was observed by FESEM. Further, to analyze the nanomechanical properties of the deposited δ-TaN coatings, such as hardness (H) and modulus (E), scratch tests were performed utilizing the nanomechanical system. Moreover, friction and wear properties of the coating and bare sample (substrate) were investigated on nano-tribometer equipment using a rotary ball-on-disk type configuration. The stainless steel (SS-316) and silicon nitride (Si3N4) balls were used as the counter materials for the tribological tests. The observations of nanomechanical tests revealed that H (GPa), E (GPa), and H/E ratio values increased from 11.83 to 28.30 GPa, 176.02 to 248.45 GPa, and 0.06 to 0.11, respectively, with the decrease of the deposition pressure. In the scratch test, the highest critical load (cohesion failure) was found for δ-TaN coating deposited at the lowest deposition pressure (0.2 Pa). Tribological results of δ-TaN coatings demonstrated average coefficient of friction (COF) value ranges between 0.066–0.092 and 0.072–0.029 against steel and Si3N4 balls, respectively. The wear rate values were observed to vary from 8.15 × 10−5 to 7.56 × 10−6 and from 1.77 × 10−3 to 8.99 × 10−6 against steel and Si3N4 balls, respectively. Generally, the average COF and wear rate decreased against 316 SS and Si3N4 balls as the deposition pressure of coatings decreased. However, the coating deposited at 0.8 and 0.6 Pa against Si3N4 ball showed early delamination of the coating, resulting in the sudden fluctuation in COF plots and higher wear rate in the range of 10−3 mm3/N.m.

Evaluation of tribo-mechanical measurements and thermal expansion of Cu-based nanocomposites reinforced by high strength hybrid ceramics

It is known that Copper’s (Cu) electrical conductivity makes it a desirable material for use in industry. Due to poor properties such as hardness, thermal expansion, and corrosion resistance, its applications are limited. This manuscript solves these problems while maintaining no breakdown in electrical conductivity. In this study, high-strength ceramics (SiC nanoparticles and graphene nanosheets) were used as reinforcements in the manufacture of Cu-based hybrid nanocomposites using powder metallurgy technique. X-ray diffraction analysis (XRD) was used to investigate phase composition and crystal size of the milled powders. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM), respectively examined the microstructure of the prepared powder powders and sintered nanocomposites. Then, various properties of the sintered samples are measured, including physical, electrical and thermal properties and wear resistance. The obtained XRD technique and TEM images showed decreases in the crystal and particle size of milled samples reaching up to 14.08 and 28.30 nm, respectively for the sample contained 8 vol. % SiC + 0.8 vol. % graphene (SG8). A surprising improvement in the mechanical properties of up to 809.15, 341.84 MPa and 336.56 GPa for microhardness, strength and longitudinal modulus for the sample containing the highest reinforcements, achieving an improvement of up to 122, 61.37 and 41 percent compared to the Cu matrix. Moreover, there was a noticeable improvement in the coefficient of thermal expansion (CTE) and wear rate values of the samples by increasing the percentages of hybrid reinforcements in the examined sintered nanocomposite samples. The Sample SG8 recorded the lowest value, decreasing by about 50.2 and 76.5% compared to the SG1 sample. Finally, adding reinforcements to the Cu matrix had a negative effect on the relative density and electrical conductivity, and the lowest values was 92.94% and8.59 × 106 S/m, respectively for the SG sample.

Effect of SiC content on the microstructure and wear behavior of cold-sprayed Al-SiC coatings deposited on AZ31 alloy substrate

Effect of SiC content on the microstructure and wear behavior of cold-sprayed Al-SiC coatings deposited on AZ31 alloy substrate

Effect of ZrO2 nanoparticles on the self-lubrication behavior of the linseed oil-loaded microcapsule/ epoxy composite coatings

Effect of ZrO2 nanoparticles on the self-lubrication behavior of the linseed oil-loaded microcapsule/ epoxy composite coatings

Determination of “tribological performance working fields” for pure PEEK and PEEK composites under dry sliding conditions

Determination of “tribological performance working fields” for pure PEEK and PEEK composites under dry sliding conditions

Experimental Comparison of Manufacturing Parameters in Automotive Friction Materials

In this study, a fixed automotive friction material content was determined and the mechanical and tribological effects of manufacturing parameters on friction materials were investigated. Parameters; pre-forming time (1-3-5 min) and pre-forming pressure (8-10-12 MPa), hot pressing time (5-10-15 min) hot pressing pressure (8-10-12 MPa) and hot pressing temperature (125-150-175 °C), curing time (4-8-12 h) and curing temperature (120-150-180 °C) were determined. The friction test of the produced samples was carried out under 0.551 MPa pressure and 7 m/s rotation speed for 90 min. In addition, the average COF, friction stability, specific wear rate, density and hardness values of the samples were calculated. According to the results obtained, the average COF value increased as the pre-forming time and pressure increased. The lowest specific wear rate among all specimens was calculated as 7.622x10-6 cm3/Nm in PFP-12 specimen. With the increase in hot pressing time, the tribological properties of friction materials improved. The highest friction stability among all samples was calculated as 79.42% in the HPT-15 sample. Although there was an increase in the average COF value with increasing hot pressing pressure and temperature, the specific wear rates increased in these parameters. The highest average COF value among all samples was obtained in the CT-12 sample with a value of 0.553. The specific wear rate increased with the increase in curing time and temperature. The highest specific wear rate among all samples was calculated 10,743x10-6 cm3/Nm in the CTe-180 sample. Finally, it has been suggested that 3 min for pre-forming time, 12 MPa for pre-forming pressure; 15 min for hot pressing time, 12 MPa for hot pressing pressure, and 150°C for hot pressing temperature; and a curing time of 8 h and curing temperature of 150 °C may be sufficient.

Evaluation of the effect of strontium and tungsten carbide on the microstructure evolution, tribological and mechanical behaviour of Al-Zn-Mg-Cu-5Sr-WC metal matrix composite

The present study focused on the experimental investigation of the metallurgical, tribological, and mechanical behavior of the developed Al-Zn-Mg-Cu-Sr-WC (Al7075-Sr-WC) metal matrix composite. The effect of the reinforcements such as strontium and tungsten carbide (WC) along with a 2 wt% magnesium as the wetting agent during the stir casting of the synthesized aluminum metal matrix composite (MMC) was investigated by varying the weight percentages. The microstructure examination was characterized using field emission scanning electron microscopy (FE-SEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS) techniques. Wear analysis and mechanical testing were conducted to study the effect of WC particles in the matrix phase by examining their wear rate, tensile strength, proof strength, and hardness values. From the mechanical and tribological tests, it was observed that there was an increase of 55% in hardness and 43% in tensile strength, along with a 31% reduction in wear rate. The secondary phases revealed from XRD analysis lead to more hardness along the refined grain boundaries. The tensile strength of the composite initially increased with a 3 wt% of WC and 5 wt% strontium due to hindrance to the dislocation movement but decreased with more reinforcement particles caused by brittleness. The hard WC particles presence has reduced the wear rate significantly due to its resistance towards abrasive wear and lubricating effect. The unique combination of a grain refiner and a binder helped develop a novel composite with superior characteristics that could replace many aerospace components made up of Al7075 alloy.

Microstructure evolution, wear and corrosion behavior of WC reinforced CoCrFeNiMn high-entropy alloy composite coatings by induction cladding

Microstructure evolution, wear and corrosion behavior of WC reinforced CoCrFeNiMn high-entropy alloy composite coatings by induction cladding

Wear Rate, Tribo-Corrosion, and Plastic Deformation Values of Co-Cr-Mo Alloy in Ringer Lactate Solution.

This study investigates the tribocorrosion performance of a cast Co-Cr-Mo alloy prepared using casting and electromagnetic stirring (EMS) at specific frequencies. The tribocorrosion behaviour of the alloy was evaluated when exposed to Ringer's lactate solution to optimize the EMS parameters and improve its properties. The research focuses on biomedical implant applications and explores how EMS affects alloy wear and corrosion resistance. As did the friction coefficient and wear volume, the wear rate of samples produced with EMS frequencies of 75 Hz and 150 Hz decreased. These improvements are attributed to the ability of EMS to refine grain size and homogenize the microstructure, thereby increasing the resistance to tribocorrosion. Techniques such as scanning electron microscopy (SEM) and profilometry were used for surface and wear analysis, while mechanical properties were evaluated through instrumented indentation tests. The findings confirm that EMS improves the alloy's durability and tribocorrosion resistance, making it highly suitable for demanding biomedical applications such as joint replacements. This highlights the importance of advanced manufacturing techniques in optimizing biomedical alloys for simulated body conditions.

The Effect of Tempering Temperature on Microstructure and Wear Behavior of Tungsten and Boron Alloyed Ni-Hard 4 White Cast Irons

This study investigates the effect of tempering temperature on the microstructure and wear resistance of high-alloy white cast iron (Ni-Hard 4) with 1.15% W and 0.5% B additions. Specimens were austenitized at 850 °C for 5 h, quenched in air, and tempered at temperatures between 250 and 650 °C for 4 h. Equilibrium and non-equilibrium thermodynamic calculations were performed using Thermo-Calc software. After the microstructural investigations, hardness testing was carried out. A pin-on-disk tribometer was used to conduct wear tests under dry sliding conditions. Microstructure and worn surfaces were examined using light and scanning electron microscopes. The results showed that increasing tempering temperature resulted in a higher volume fraction of carbides. It was found that tempering at 550 °C for four hours increases resistance to wear giving the lowest measured values of weight loss and wear rate. Accordingly, tempering allows the precipitation of fine carbides in the martensitic matrix which may increase wear resistance.